Improvement in electro-magnetic telegraphs



2 sheets- Shana l.' 0LMSTED.` Electro-Magnetic Telegraph. No. 167,685. Patented.sept.14,1s75.

mijn/Aww. Ewan/ll.

WW W @y ab@ wmf@ Nrrnn lS'LLA'IES PATENT OFFICE,

JOSEPH OLMSTED, OF PROVIDENCE, RHODE ISLAND, ASSIGNOR ,OE ONE- HALF HIS RIGHT TO CHARLES G. MCKNIGHT AND GEORGE CHATTER- TON, OF SAME PLAGE.

IMPROVEMENT INELECTRO-MAGNETIC T'ELEGRAPHS. v

Specification forming-part of Letters Patent No. 167,685, dated September 14, 1875 ;4 application filed May 15, 1875.

To all whom it may concern:

Be it known that I, J osnrn OLMsrnD, of Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Electro-Magnetic Telegraphs; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, making a part of this specification, in whic Figure l represents in perspective a transmitting-instrument with two keys for transmitting two messages at the saine time-one through the positive and the other through the negative current. Fig. 2 represents in perspective one ofthe receivin g-instruments, there bein gtwo-one for each current and messageboth exactly alike in construction, but with their polarities reversed, one only being shown in the drawing, as both would appear therein exactly` alike. Fig. 3 represents a diagram showing how the conductors are closed and opened for alternating the currents through the line and relays. l,

My invention consists in combining, with alternating currents running through the line and relays, two keys for transmitting independent messages at one and the same time. It further consists in the combination of a double-keyed transmitting-instrument with two receiving-instruments having the polarities of their armatures reversed.

My invention, relating to what is known as 4 a duplex telegraph, is carried out by reversing ures and diagram, Fig. l showing what I term a motor for changing the poles of the battery in relation to the line, said motor being run by a local battery, arranged for that purpose through or by means of an automatic breakpiece or circuit-closers.

In the diagram, Fig. 3, a a. represent the break-pieces or circuitclosers, and h la represent the two keys. L L and G G represent contactpoints 4for the alternating current. B B rep'- resent springs, which are connected to or with the battery-wires which run to each pole of the battery, and keep in rapid vibration between the contact-points L L and G G, so that when the springs B B are in contact with the points L L the negative pole of the battery is closed with the-line, and when in contact with the points G G, the negative pole is closed with the ground, thereby reversing the current throughout the circuit and throughout therelays. When the current is opened by means ofthe key 7c it will ow in one direction only.

The instruments used for receiving messages are two electro-magnets, (one onlybein g shown in the drawing, Fig. 2,) with armatures ofy opposite polarities,-F representing the polarizedl y armature, and m the.relaymagnet, the poles of'which are reversed alternately when tho keys are both closed, and the arm D attached to the polarized armature F is kept in rapid vibrationbetween the adjustable screws a: y;

but when the circuit is broken at key h the It will be readily understood, then, that when the currents are passing (either the or or both) that the armature-levers of the appropriate polarized relays are vibrating with such rapidity that when they touch against the back stops the closures are so exceedingly momentary that the sounders are not affected thereby. Now, if the key controlling the current be opened, that current is cut off from the line, and the relay whose armature and coils are so adjusted that the armature is attracted `by the current ceases to act, and the spring pulls `the lever against the back stop, causinga complete closure of the local circuit to its sounder so long as such currentis cut off from the line. When the key isdepressed the same result ensues in the relay; and, when both are simultaneously depressed, the same result ensues in both.

It is evident that each station maybe provided with -1- and keys and+ and relays, (then one commutator only being necessary for the 1ine,) and that two messages may be sent simultaneously in opposite directions as well as in the same direction, the principle and operation being the same.

By this system and construction the Morse alphabet can be easily made and used by operatin g separately or' together without one transmission interfering with the other.

. In the diagram, Fig.` 3, the motor-battery is represented at A, the main battery at C, and the'ground-connection at E. The wire for the positive current is shown .at b, and` that for the negative current at c, while d represents the linefwire. On the right of the diagram, showing the receiving-currents, H represents the local battery for the permanent magnet or polarized armature O. P represents the local battery for the polarized armature Q, and Iis the ground connection. In Fig. 2, representing one of the receiving instruments, e @represent the conductors to the sounder. J, Figs. l and 2, represent the posts on the base or table K, for making the wire-connections, as shown in the diagram. The arm M, with its adjustable Weight N, is for the purpose of regulating the vibration of thesprin gs B between the contactpoints G and L. flhe springs B, as well as the regulating-arm M, are attached to a vibrator or armature, f. The telegraph is represented as in condition for making the Morse alphabet when the circuit of the main line is open.

When the key li is opened, and that lc is closed, then the current passes throughk to ing currents, a pair orseries of pairs of keys,

and a pair or series of pairs of relays, one of the keys of a pair acting to` cut oi from the line the -lcurrents only, the other to cut olf, the currents', and one relay of each pair being arranged so as to vibrate by the passage therethrough of currents, and the other by the` f currents, and both relays arranged to give a signal or close a local circuit upon the cutting oii' from the line of the currents affecting it, substantially as and for the purposes described. n

JOSEPH OLMSTED. Witnesses:

A. B. SroUeHroN, EDMUND MASSON. 

